This project will attempt to define the relationships which exist between dietary protein, nutritional osteoporosis and periodontal diseases. To do so, experiments will be carried out in rats to determine the effects of acute and chronic protein excess or deficiency on bone, tooth and calcium metabolism. Calcium absorption and excretion, collagen synthesis and metabolism, mineralization of bone and dental tissues and possible hormonal involvements will be studied to determine which physiological and biochemiccal involvements will be studied to determine which physiological and biochemical processes are affected during the development of nutritional osteoporosis and other related lesions.